From the recent viewpoint of laborsaving it is required to simplify and accelerate the working of incorporating a brick into a slide gate valve, and therefore it is adopted o integrally set a slide plate and a chute nozzle. Conventionally, in such an integrating method it has been general to set the slide plate and the chute nozzle by using a filler such as mortar or castable in a one-body metal casing which is formed to envelop the side surface and bottom surface of said slide plate and the side surface of said chute nozzle.
However, such a system has demerits in that parallelism can hardly be retained between the sliding surface and the bottom surface of the metal casing because of the fluidity of the filler, and a long period of time is required for the complete hardening of the filler.
To remove such demerits the applicant of the present application previously proposed to employ "an Accommodation Structure of Refractory for Slide Valve" (Utility Model Publication No. 2-35405).
By adopting such an accommodation structure it has become to easily take a parallelism of the slide plate, to accelerate adhesion, and to easily manufacture the refractory block for slide gate valve by ordinary cutting, welding or the like of the steel material. However, with such an accommodation structure the steel plate fixed to the bottom surface of the slide gate valve has no sufficient strength, and it is known that because of thermal expansion of the metal casing a clearance is likely to occur between the slide plate or seal plate and the mortar-bonded seal nozzle or the submerged nozzle, troubles occasionally occur due to metal insertion or the like, and a complete integration is impossible.
Conventionally, a plate brick and a submerged nozzle are of split type. However, the object of the present invention is to provide a refractory block usable for multi-continuous casting in such a way that said plate brick and said submerged nozzle are formed integrally, the integral body is covered by a metal casing so that it has in combination a sufficient mechanical strength, a corrosion resistancy, an anti-spalling property and the like whereby a clearance is not created in the joint portion, and a nozzle blocking caused by the metal insertion or air suction is prevented so as to improve the quality of steel.